Power winch for cranes and the like

ABSTRACT

The payload cable of a crane or the like is reeled in and payed out by a winch drum which is positively driven at all times by a pair of hydraulic motors. When lifting a payload, these two motors are operated in a parallel mode to provide maximum line pull at slower speed. The motors may be operated in the series mode to halve the line pull while the line speed is doubled. This mode of operation is employed to drop the hook ball of the crane rapidly. The winch additionally features a compact planetary gear reduction unit and an intercoacting one-way active clutch and disc brake arrangement for the winch drum shaft. The main shaft bearings are inboard of the clutch and brake housing and the latter components are easily accessible for servicing. A simplified hydraulic control circuit for the winch motors renders the operation of the winch safe, efficient and rapid with out resort to a free-fall mode for the hook ball or free-wheeling of the winch drum.

R. 1.. STERNER ETAL 3,726,801

POWER WINCH FOR CRANES AND THE LIKE A ril 1973 2 Sheets-Sheet 1 Filed March 25, 1971 April 10, 1973 R. L. STERNER ETAL 3,726,301

POWER WINCH FOR CRANES AND THE LIKE 2 Sheets-Sheet 2 Filed March 25, 1971 $2 i In J H & EN. SN 11] mm mm E m 2 w a m s a u w i! r; T m I: a @m a M United States Patent Cfice 3,726,861 Patented Apr. 10, 1973 3,726,801 POWER WINCH FOR CRANES AND THE LIKE Russell L. Sterner, Greencastle, and Henry A. Kohler,

Waynesboro, Pa, assignors to Walter Kidde & Company, Inc., Clifton, NJ.

Filed Mar. 25, 1971, Ser. No. 127,955 Int. Cl. B6611 1/00 US. Cl. 254-187 R 4 Claims ABSTRACT OF THE DISCLOSURE The payload cable of a crane or the like is reeled in and payed out by a winch drum which is positively driven at all times by a pair of hydraulic motors. When lifting a payload, these two motors are operated in a parallel mode to provide maximum line pull at slower speed. The motors may be operated in the series mode to halve the line pull while the line speed is doubled. This mode of operation is employed to drop the hook ball of the crane rapidly. The winch additionally features a compact planetary gear reduction unit and an intercoacting one-way active clutch and disc brake arrangement for the winch drum shaft. The main shaft bearings are inboard of the clutch and brake housing and the latter components are easily accessible for servicing. A simplified hydraulic control circuit for the winch motors renders the operation of the winch safe, efficient and rapid without resort to a free-fall mode for the hook ball or free-wheeling of the winch drum.

The objective of the invention is to provide a more economical and more efiicient winch for the payload cable of a crane or like machine. The invention provides such a winch which is driven by a pair of hydraulic motors and whose operation is safely controlled at all times through the interaction of a unique arrangement of a one-way active clutch on the winch drum shaft and a surrounding disc brake coupled with winch drum shaft through the outer race of the clutch and rendered normally active by springs in a readily removable housing. The mounting of the clutch, brake and associated components on the end of the winch housing and outwardly of the drive gearing and main shaft bearings renders servicing and replacement of parts very simple and also renders the overall construction of the winch simple and economical.

The hydraulic control circuit for the two drive motors and the disc brake features a series-parallel spool valve to feed fluid to the motors in a parallel or series mode, as required. The circuit includes an over-center valve in series with the series-parallel spool valve to control brake release pressure in the system, which control is necessary for the proper operation of the winch. The over-center valve allows a rapid build up of brake release pressure for lowering a load. If the overhauling load on the winch drum attempts to run away, the pressure to the pilot assist port of the over-center valve and the brake release pressure will drop. The balancing action of the circuit will assure that the load will always be lowered dynamically, that is, driven downwardly by the motors, and there is no free-fall or free-wheeling mode of operation. However, the speed of lowering a hook ball or the like is as rapid by use of the invention as it would be with a free-falling mechanism and the usual automatic checks or controls which limit the free-fall.

Other features and advantages of the invention will be apparent during the course of the following detailed description.

BRIEF DESCRIPTION OF DRAWING FIGURES FIG. 1 is a central vertical section through a power winch embodying the invention;

FIG. 2 is a hydraulic control circuit schematic; and FIG. 3 is a schematic end view of the winch in the control circuit.

DETAILED DESCRIPTION Referring to the drawings in detail wherein like numerals designate like parts, the power winch comprises a main frame including frame ends 10 and 11 which contain the main bearings 12 and 13 for a winch drum 14 journaled thereon. The winch drum is adapted to receive a cable, not shown, such as the payload cable of a construction crane. Extending axially through the drum 14 and beyond the ends thereof is a main drive shaft 15 having splined portions 16 and 17 near its opposite ends. The splined portion 16 of the main drive shaft is keyed within a splined opening in the hub of a large spur gear 18 meshing with and driven by a smaller pinion gear 19, journaled in bearings 20 and 21 on the housing end 10 and an adjacent support plate 22 which also serves to enclose the gears 18 and 19 and associated parts. The plate 22 thus forms a removable-part of the winch main frame. The pinion 19 is coupled with and driven by the output shaft of a first reversible hydraulic motor 23. This motor per se is conventional and need not be described in detail. Diametrically opposite the first motor 23 and pinion 19 is a second identical hydraulic motor and pinion shown displaced by phantom lines in FIG. 1, the second motor being indicated by the numeral 23. The second pinion in mesh with the gear 18 diametrically opposite the pinion 19 is indicated by the numeral 19'. As will be fully explained, the two motors 23 and 23 are adapted to be driven either in a series mode or parallel mode to impart to the winch drum a higher or a lower rotational speed and a greater or lesser degree of pulling torque transmitted to the cable.

The splined portion 17 of the main shaft 15 is similarly coupled to a sun gear 24, meshing with and supported by three planetary gears 25, only one of which is shown in the cross sectional view. These planetary gears mesh with a fixed ring gear 26 firmly seated in a recess in the frame end 11. The frame end 11 has an outer cover plate 27, the removal of which provides ready access to the planetary gearing which constitutes speed reduction gearing between the main shaft 15 and winch drum 14. The planetary gears are each coupled by their pin axles 28 to a planetary gear cage 29 which rotates about the shaft 15 and is splined at 30 to an extension hub 31 of the winch drum 14 to drive the winch drum. Suitable seals 32 are provided between the shaft 15 and the drum 14 which rotates relative thereto, as shown in FIG. 1. The shaft 15 is supported in a bearing 32 held in a recess in the frame end 10 and by the sun gear 24 which is supported on center by the three symmetrically spaced planetary gears 25. A bushing or sleeve bearing 32a mounted within the extension hub 31 of the winch drum inwardly of the adjacent seal 32 serves to support shaft 15 during assembly of the winch.

The main shaft 15 includes a reduced end extension 33 extending outwardly of the plate 22 and upon this extension the inner race 34 of a one-way free-wheeling clutch 35 is keyed, as indicated at 36. The outer race 37 of the one-way free-wheeling clutch has its periphery splined at 38 and these splines or teeth are interlocked with corresponding interior teeth on a series of brake pressure plates or discs 39 intervened by friction discs 40 whose external teeth are engaged with splines or teeth 41 on the interior of a housing cap 42 bolted to support plate 22 by bolts 43. A piston body 44 is disposed slidably in the bore of the housing cap 42 and is urged inwardly toward the stacked brake pressure plates and friction discs .by a series of springs 45 preferably numbering twelve in circumferentially spaced relation. The friction brake composed of the discs 39 and 40 is thus biased to the on or active condition by the piston body 44 and biasing springs 45. When the friction brake is active, the outer race 37 of the one-way free-wheeling clutch is locked to the housing cap 42. The inner clutch race 34 which may turn in one direction allows the shaft 15 and the winch drum to turn in that direction. The one-way clutch and the brake prevent any rotation of the main shaft and drum in the opposite direction at this time.

In order to release the friction brake, a fluid pressure line 46 is connected centrally at 47 to the relatively stationary housing cap 42 and delivers fluid under pressure through a central axial port 48 and radial ports 49 to a chamber 50 between the piston body 44 and a fixed sealing head 51 on the housing cap. Fluid pressure in the chamber 50 will force the piston body outwardly compressing the springs 45 and relieving the disc brake from pressure and therefore releasing it. When released, the outer clutch race 37 may turn relative to the housing cap 42 and the shaft 15 may turn even though the two clutch races 34 and 37 are locked in one direction.

It will be observed that the concentrally arranged disc brake and one-way active clutch and the piston means to activate the brake are all compactly arranged in the readily removable housing cap 42 outwardly of the support plate 22. The drive gearing 18-19 and the main bearings 12 and 13 for the drum are all disposed inwardly of this coacting clutch and brake mechanism and need not be disturbed when either the clutch or brake require servicing. Servicing of these elements is made quite easy by the use of the removable housing cap 42 resulting in ready accessibility of the parts adjacent to the shaft extension 33. At the other end of the winch, the planetary reduction gearing is similarly arranged outwardly of the main bearing 13 and is rendered accessible by the readily removable cover plate 27, already described.

Referring to FIGS. 2 and 3, the mode of operation of the winch may be described as follows.

When lifting a payload with the winch, hydraulic fluid at the appropriate pressure and flow rate is introduced through a T 52 from a line 53 leading from a main control valve 54. The main control valve 54 is shown in the neutral or closed position in FIG. 2. The customary boost valve 54' is also provided and is in the neutral position and connected in parallel with the main valve 54. Pumps 55-55 are provided to supply the two valves 54 and 54 with fluid under pressure, the reservoir being indicated at 56. It will be understood that when operating the winch in a lifting mode and introducing fluid through the T 52 from supply line 53, the control valve 54 is positioned with its supply and return ports 57 and 58 in registry with the supply line 53 and a return line 59, FIG. 2. From the T 52, fluid enters an over-center valve 60 having a one-way opening check 61 and a pilot pressure controlled poppet 62. The over-center valve 60 is of a type marketed by Fluid Controls, Inc., 8341 Tyler Blvd, Mentor, Ohio, 44601, under designation Pilot Assisted Style for Oil-to 80 g.p.m., 3000 psi. The overcenter valve is basically a counter-balance valve with a pilot override or assist on the relief valve section. The load is raised by free-flow of oil through the check section 61. With the control valve 54 centered as shown, the winch load is locked (relief must be set at least 1.3 times higher than the maximum load induced pressure). To lower the load, pilot pressure is required which effectively reduces the relief valve setting. Calculations for pilot pressure requirement to move the load is simply:

(Relief Setting) (Load Pressure) Pilot Pressure Pilot Ratio Required Therefore, in the lifting mode, the fluid from the T 52 will pass through the check section 61 of over-center valve 60 and will be delivered by a line 63 to a seriesparallel valve 64 which is indicated as in the lifting mode and is positioned to operate the two hydraulic motors 23 and 23' in parallel for maximum payload line pull at relatively slow speed. As shown, fluid from the line 63 is delivered by a line 65 to the motor 23 and is returned from the motor through a line 66 and back through the valve 64 to a return line 67, leading to another T 68 and finally to return line 59. Parallel supply and return lines 69 and 70 for the boost valve 54' are also indicated in a conventional manner. In like manner, fluid from the supply line 63 is delivered by the valve 64 to the parallelconnected motor 23' through a line 71 and from the motor 23' fluid is returned through another line 72 through the valve '64 to the return line 67.

It is apparent that the two motors 23 and 23 may also be operated in series as when lowering a load on the winch drum and at this time the line pull is halved and line speed is doubled. In the series mode, the valve 64 is shifted to its second position and fluid from the line 63 is delivered to the motor 23 through line 71 and then through line 72 is delivered in series to the motor 23 and finally from this motor through the line 66 and valve 64 is delivered to the return line 67.

During this operation for lifting a payload, the inner race 34 of the one-way free-wheeling clutch is free to rotate. The brake discs 39 and 40 are compressed and loaded by the springs 45 and the disc brake is active. When the control valve 54 is moved away from neutral or closed or should a hydraulic failure occur in the system, the spring-loaded disc brake will always hold the load since the overrunning clutch is locked and will not permit rotation of the dnum 14.

When lowering the payload, the control valve 54 is shifted so that the ports 73 and 74 will register with the lines 59 and 53, respectively. Pressurized fluid will now be delivered through the line 59 to the T 68. It will be noted that the boost valve 54' can also deliver fluid to the T 68 through the line 70. From the T 68, fluid is delivered through line 67 to the series-parallel valve 64 and to the hydraulic motors 23 and 23' in the manner already described. The winch cannot lower the payload until hydraulic brake release pressure in the chamber 50 is built up through the line 46. Brake release pressure builds up rapidly because the return line 63 through the over-center valve 60 is blocked. Simultaneously, the over-center pilot assisted pressure through a line 75 builds up and permits the hydraulic fluid to flow through the valve 60 by shifting the element 62.

If the overhauling load on the winch drum attempts to run away during lowering, the pressure to the pilot assist port of the over-center valve and the brake release pressure in the chamber 50 drops. The over-center valve poppet 62 tends to close, thus building up the pilot assist pressure in the valve 60 and increasing the pressure against the brake release piston body 44 in the chamber 50. The balancing of the pilot assist pressure in the over-center valve with complete brake release will assure lowering the load dynamically without a jerky action. A very delicate balance and control is automatically maintained by the system and this balance is an important feature of the invention.

The pilot assist pressure to the over-center valve 60 must be greater than the brake release pressure through the line 46 to chamber 50 to assure proper coordination between brake release and dynamic lowering of the payload.

Line speeds from 306 feet per minute at low speed to 612 feet per minute at high speed are obtainable with the winch. Single line pulls is 17,000 pounds at low speed and 8,500 pounds at high speed. All internal parts of the winch as shown in FIG. 1 run in oil.

A brake cooling line 46' provides a flow of fluid to the housing cap 42. Hydraulic fluid is supplied from filter 76 on the reservoir 56 and the drain lines from the two motors 23 and 23. The coolant fluid flow from the housing cap 42 into the housing end through plate 22. The cooling oil is used to lubricate bearings 20, 21 and 32, and to provide lubrication for the smaller pinion gears 19 and 19', and large spur gear 18. The flow of cooling fluid is returned to the reservoir through hydraulic line 77 connected through plate 22.

The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof but it is recognized that various modifications are possible within the scope of the invention claimed.

We claim:

1. A power winch comprising a frame including separated frame ends, main winch drum bearings in the frame ends, a winch drum journaled for rotation on said bear ings, a unitary uninterrupted main drive shaft extending axially through the winch drum and outwardly of the frame ends, planetary speed reduction gearing coupled to one end of the main drive shaft outwardly of one main winch drum bearing and including a planetary gear cage coupled directly to the hub of said winch drum outwardly of said one main winch drum bearing, a driving spur gear coupled directly to the opposite end portion of the main drive shaft outwardly of the other main winch drum bearing, a support and cover plate on the outer side of the frame end adjacent said spur gear and covering the latter, a pair of diametrically opposed hydraulic drive motors on the support and cover plate and disposed outwardly thereof, drive pinions coupled with said motors and meshing with the spur gear to drive it, said main drive shaft having an end extension outwardly of said support and cover plate, a one-way active roller bearing clutch including an inner race coupled to said shaft extension and a surrounding outer race free to turn in one direction only, a disc brake assembly having plural discs immediately surrounding said clutch in the same axial location as the clutch and having alternate discs interlocked with the outer race of the clutch and having alternate intervening discs, a housing cap surrounding and covering the disc brake and clutch and removably secured to the support and cover plate, said alternate intervening discs interlocked with the side wall of the housing cap, a piston element within the housing cap bearing axially against the disc brake, springs within the housing cap urging the piston element against the disc brake and rendering the brake active to prevent rotation of the outer race of the clutch relative to the housing cap, and means connected with the housing cap to admit pressurized fluid thereto in a manner to move the piston element away from the disc brake and against the springs to release the disc 'brake.

2. The structure of claim 1, and one of said frame ends having an outwardly opening chamber receiving and housing said reduction gearing, and a removable cover plate for the open end of the frame end chamber.

3. The structure of claim 1, and bearing for the rotational support of said main drive shaft, one such bearing mounted in the frame end adjacent the driving spur gear and inwardly thereof but outwardly of the adjacent main winch drum bearing, the other bearing mounted in a hub extension of said winch drum inwardly of said planetary speed reduction gearing and outwardly of the other main winch drum bearing, said planetary gear cage coupled to the hub extension of the winch drum to drive it.

4. A hydraulic power winch and controls comprising a winch drum for operating a payload cable, a power drive for said drum including a main drive shaft and gearing coupled to said shaft, a pair of hydraulic motors operatively connected to said gearing, a one-way active clutch having an inner race coupled to the drive shaft and an outer race which is free-wheeling in one direction and lockable against rotation in the opposite direction, a brake device coupled with said outer race to lock the outer race when the brake device is active, resilient pressure means engaging the brake device to maintain it normally active, fluid pressure brake release means working in opposition to the resilient pressure means to release the brake device, a series-parallel valve connected with said hydraulic motors to operate them selectively in parallel or in series, a main fluid control valve operable to cause the winch drum to turn selectively in a load lifting mode or load lowering mode, a pair of fluid delivery and return devices connected between the main control valve and said series-parallel valve, and an over-center valve connected between said delivery and return devices and said series-parallel valve and including a one-way opening fluid check passage in series with one of said delivery and return devices and a pilot assisted relief section having a fluid connection with the other of said delivery and return devices, there being a fluid connection between said brake release means and said series-parallel valve, whereby a balancing of brake release pressure and pilot assist pressure is automatically maintained when the winch drum is operating in a load lowering mode, said pilot assisted relief section and the fluid connection to the brake release means being connect- 0 ed to the other of said delivery and return devices, whereby fluid under pressure is simultaneously delivered thereto during the load lowering mode.

References Cited UNITED STATES PATENTS 3,244,405 4/1966 Hanning 254-186 2,345,662 4/1944 Fox et al. 254l86 2,903,852 9/1959 Bottoms -53 R 3,438,201 4/1969' Nash et al 6053 W 3,296,893 l/ 1967 Shatter et al 254-187 X 3,128,861 4/1964 Trondsen 254-187 X EVON C. BLUNK, Primary Examiner M. F. MAFFEI, Assistant Examiner U.S. Cl. X.R.

254- F. H.; 192-12; 60-53 R 

